Lens barrel with built-in blur correction mechanism

Abstract

A lens-driver for driving a lens for compensating image blur caused by camera shaking has two driving-levers. In each driving-lever, one end is rotatably connected to a lens frame via a holding shaft and the other end is rotatably supported by a rotation shaft. Two driving levers are arranged generally on one straight line, and there is formed a generally perpendicular angle by a line connecting the holding shaft of one driving-lever and an optical center of the lens, and a line connecting the holding shaft of the other driving-lever and the optical center. Another lens-driver has two driving mechanisms. One driving mechanism drives the lens, and the other driving mechanism drives a shutter mechanism or an aperture mechanism. In the lens barrel, one mechanism occupies one half area and the other mechanism occupies the other half area.

What is claimed is:  
     
       1. A lens driving mechanism, comprising: 
       a lens;  
       a frame for holding the lens;  
       a first lever, one end of which is rotatably connected to the frame via a first holding shaft which extends parallel to an optical axis of the lens into a hole ptovided in the frame, and the other end of which is rotatably supported by a first rotation shaft, rotational movement of the first lever causing the frame to swing in a first direction; and  
       a second lever, one end of which is rotatably connected to the frame via a second holding shaft which extends parallel to the optical axis of the lens into another hole provided in the frame, and the other end of which is rotatably supported by a second rotation shaft, rotational movement of the second lever causing the frame to swing in a second direction which is approximately perpendicular to the first direction,  
       wherein the first holding shaft, the first rotation shaft, the second holding shaft, and the second rotation shaft are generally arranged on one straight line, thereby minimizing a distance change between the first and second holding shafts during the rotation movements of the first and second levers, and  
       wherein there is formed a generally perpendicular angle by a line connecting the first holding shaft and an optical center of the lens, and a line connecting the second holding shaft and the optical center of the lens.  
     
     
       2. The lens driving mechanism as claimed in  claim 1 , wherein the first lever and the second lever are arranged in a plane perpendicular to the optical axis so as to be symmetrical with respect to a line passing through the optical center. 
     
     
       3. The lens driving mechanism as claimed in  claim 1 , wherein the first lever and the second lever are driven independently to each other, 
       wherein the first lever is driven by a first shape memory alloy in one direction around the first rotation shaft and by a first spring in the other direction around the first rotation shaft, and  
       wherein the second lever is driven by a second shape memory alloy in one direction around the second rotation shaft and by a second spring in the other direction around the second rotation shaft.  
     
     
       4. The lens driving mechanism as claimed in  claim 3 , wherein the first shape memory alloy and the second shape memory alloy are wire-shaped, and they are overcrossed to each other in a lens barrel. 
     
     
       5. A lens driving mechanism, comprising: 
       a lens barrel;  
       a lens supported in the lens barrel;  
       a first-driving mechanism for driving the lens, which is accommodated in the lens barrel and occupies only a first half of a total area of the lens barrel at a cross section perpendicular to an optical axis of the lens; and  
       a second-driving mechanism for driving a member which is other than the lens driven by the first-driving mechanism, the second-driving mechanism being accommodated in the lens barrel and occupies only a second half different from the first half of the total area of the lens barrel at the cross section, wherein the first half and the second half constitute the total area in the cross section of the lens barrel.  
     
     
       6. The lens driving mechanism as claimed in  claim 5 , wherein the second-driving mechanism drives a shutter mechanism arranged near the lens. 
     
     
       7. The lens driving mechanism as claimed in  claim 5 , wherein the second-driving mechanism drives an aperture mechanism arranged near the lens. 
     
     
       8. The lens driving mechanism as claimed in  claim 5 , wherein the first-driving mechanism comprises: 
       a first driving-lever, rotatable around a first rotation shaft, for driving the lens;  
       a first shape memory alloy, which drives the first driving-lever;  
       a second driving-lever, rotatable around a second rotation shaft, for driving the lens; and  
       a second shape memory alloy, which drives the second driving-lever.  
     
     
       9. The lens driving mechanism as claimed in  claim 5 , wherein the first-driving mechanism comprises a first driving-lever rotatable around a first rotation shaft and a second driving-lever rotatable around a second rotation shaft, 
       wherein the first driving-lever has a first holding shaft which is rotatably connected to a frame for holding the lens via a first holding shaft which extends parallel to an optical axis of the lens into a hole provided in the frame, and the second driving-lever has a second holding shaft which is rotatably connected to the frame for holding the lens via a second holding shaft which extends parallel to the optical axis of the lens into another hole provided in the frame, so that when one of the first driving-lever and the second driving-lever rotates around its rotation shaft, the lens is driven around the first holding shaft or the second holding shaft which belongs to the other of the first driving-lever and the second driving-lever.  
       wherein the first holding shaft, the first rotation shaft, the second holding shaft, and the second rotation shaft are generally arranged on one straight line, and  
       wherein there is formed a generally perpendicular angle by a line connecting the first holding shaft and an optical center of the lens, and a line connecting the second holding shaft and the optical center of the lens.  
     
     
       10. The lens driving mechanism as claimed in  claim 6 , further comprising a blur correction unit which accommodates the first-driving mechanism, and a shutter unit which accommodates the second-driving mechanism, 
       wherein the blur correction unit has a first screw hole and the shutter unit has a second screw hole, the first screw and the second screw being aligned on one straight line, and  
       wherein the blur correction unit and the shutter unit are jointly fixed to the lens barrel by using one screw which engages into the first screw hole and the second screw hole aligned with each other.  
     
     
       11. The lens driving mechanism as claimed in  claim 7 , further comprising a blur correction unit which accommodates the first-driving mechanism, and an aperture unit which accommodates the second-driving mechanism, 
       wherein the blur correction unit has a first screw hole and the aperture unit has a second screw hole, the first screw and the second screw being aligned on one straight line, and  
       wherein the blur correction unit and the aperture unit are jointly fixed to the lens barrel by using one screw which engages into the first screw hole and the second screw hole aligned with each other.  
     
     
       12. The lens driving mechanism as claimed in  claim 8 , wherein the first lever and the second lever are driven independently to each other, 
       wherein the first lever is driven by a first shape memory alloy forcing the first lever in one of two rotational directions around the first rotation shaft and a first spring forcing the first lever in the other thereof around the first rotation shaft, and  
       wherein the second lever is driven by a second shape memory alloy forcing the second lever in one of two rotational directions around the second rotation shaft and a second spring forcing the second lever in the other thereof around the second rotation shaft.  
     
     
       13. A lens driving mechanism, comprising: 
       a lens;  
       a frame for holding the lens;  
       a first lever, one end of which is rotatable connected to the frame via a first holding shaft which extends parallel to an optical axis of the lens, and the other end of which is rotatably supported by a first rotation shaft, rotational movement of the first lever causing the frame to swing in a first direction; and  
       a second lever, one end of which is rotatably connected to the frame via a second holding shaft which extends parallel to the optical axis of the lens, and the other end of which is rotatably supported by a second by a second rotation shaft, rotational movement of the second lever causing the frame to swing in a second direction which is approximately perpendicular to the first direction,  
       wherein the first holding shaft, the first rotation shaft, the second holding shaft, and the second rotation shaft are generally arranged on one straight line, thereby minimizing a distance change between the first and second holding shafts during the rotation movements of the first and second levers, and  
       wherein there is formed a generally perpendicular angle by a line connecting the first holding shaft and an optical center of the lens, and a line connecting the second holding shaft and the optical center of the lens.  
     
     
       14. The lens driving mechanism as claimed in  claim 13 , wherein the first lever and the second lever are arranged in a plane perpendicular to the optical axis so as to be symmetrical with respect to a line passing through the optical center. 
     
     
       15. The lens driving mechanism as claimed in  claim 13 , wherein the first lever and the second lever are driven independently to each other, 
       wherein the first lever is driven by a first shape memory alloy in one direction around the first rotation shaft and by a first spring in the other direction around the first rotation shaft, and  
       wherein the second lever is driven by a second shape memory alloy in one direction around the second rotation shaft and by a second spring in the other direction round the second rotation shaft.  
     
     
       16. The lens driving mechanism as claimed in clam  15 , wherein the first shape memory alloy and the second shape memory alloy are wire-shaped, and they are overcrossed to each other in a lens barrel. 
     
     
       17. A lens driving mechanism, comprising: 
       a lens with a frame for holding the lens;  
       a first lever which is rotatably supported by a first rotation shaft and connected to the frame by a first holding shaft for driving the lens via the frame; and  
       a second lever which is rotatably supported by a second rotation shaft and connected to the frame by a second holding shaft for driving the lens via the frame;  
       wherein the first and second rotation shafts and the first and second holding shafts are parallel to an optical axis of the lens, and arranged in respective positions which are generally on one straight line in a plane perpendicular to the optical axis.  
     
     
       18. The lens driving mechanism as claimed in  claim 17 , 
       wherein the first lever and the second lever are arranged in the plane perpendicular to the optical axis so as to be symmetrical with respect to a line passing through the optical center.  
     
     
       19. The lens driving mechanism as claimed in  claim 17 , 
       wherein the first lever and the second lever are driven independently to each other;  
       wherein the first lever is driven by a first shape memory alloy in one direction around the first rotation shaft and by a first spring in the other direction around the first rotation shaft; and  
       wherein the second lever is driven by a second shape memory alloy in one direction around the second rotation shaft and by a second spring in the other direction around the second rotation shaft.  
     
     
       20. The lens driving mechanism as claimed in  claim 19 , 
       wherein the first shape memory alloy and the second shape memory alloy are wire-shaped, and they are overcrossed to each other in a lens barrel.